When both of the LeoManagers are down and you try to restart a LeoManager that is NOT the one terminated at last, you can not restart the LeoManager because a sprit-brain could happen. If you make sure there is no case the data inconsistency could happen due to a sprit-brain then do leo_manager start force_load that allows you to restart a LeoManager in such cases. Please refer What is the significance of a Mnesia Master Node in a cluster for more information.